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Not long ago, actually watching something being ripped apart as it falls
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towards a giant black hole would be science fiction.
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But this is becoming reality for astronomers using ESO’s Very Large Telescope.
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This is the ESOcast!
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Cutting-edge science and life behind the scenes of ESO,
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the European Southern Observatory.
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Hello, and welcome to the ESOcast.
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In this episode we will see how science fiction has turned into science fact
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as astronomers observe the progressive destruction of a cloud of gas
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that’s being pulled in by a supermassive black hole.
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ESO telescopes have been used to track the motion of stars
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around the giant black hole at the centre of our galaxy for 20 years.
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This black hole’s mass is a hefty four million times that of the Sun,
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earning it the title of supermassive black hole.
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Although it is huge,
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this black hole is currently supplied with little material and is not shining brightly,
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but this is about to change.
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Using ESO’s Very Large Telescope,
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a team of astronomers has discovered a new object
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that is heading almost straight towards the black hole at vertiginous speed.
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The object is not a star, but a cloud of gas.
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The cloud consists mainly of hydrogen gas,
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gas which we see anyhow in the galactic centre all over the place.
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This particular cloud weighs more or less three times the mass of Earth.
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So it’s a rather small and tiny blob only,
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but it glows very brightly in the light of the stars which are surrounding the cloud.
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As the astronomers watched,
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the cloud has been picking up pace as it gets closer to the giant black hole.
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Its speed has doubled in the last seven years
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and it is now speeding towards the black hole at more than 8 million km/h.
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The astronomers have already seen the cloud’s outer layers becoming
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more and more disrupted over the last few years as it approaches the black hole.
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But the exciting part is yet to come.
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The Black hole, imagine it sitting here,
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has a tremendous gravitational force
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and the cloud, as it comes in, it will be elongated and stretched,
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it will become essentially like spaghetti.
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It will be elongated and falling into the black hole.
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The next few years will be really fantastic and exciting
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because we are probing the territory.
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Here this cloud comes and gets disrupted,
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but now it will begin to interact with the hot gas right around the black hole.
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We have never seen this before.
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No one knows what will happen next.
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The cloud will probably heat up
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and may start to emit powerful X-rays as it gets disrupted.
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In the end the material will eventually disappear by falling into the black hole.
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For the scientists,
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this event is truly a unique chance to probe the hot gas around the black hole.
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This process of how material gets into the black hole really is not clear to us
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we don’t understand it in any detail.
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And here in the galactic centre we have an opportunity so to speak
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to have a probe of this process.
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How material really gets added to the black hole, and what the physical processes are,
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how the interactions happen in this very central region.
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That’s a fantastic opportunity.
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This is indeed science fiction becoming science fact.
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ESOcast is produced by ESO, the European Southern Observatory.
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ESO, the European Southern Observatory,
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is the pre-eminent intergovernmental science and technology organisation in astronomy,
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designing, constructing and operating the world’s most advanced ground-based telescopes.
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Transcription by ESO; translation by —
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Now that you've caught up with ESO,
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head 'out of this world' with Hubble.
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The Hubblecast highlights the latest discoveries
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of the world´s most recognized and prized space observatory,
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The NASA/ESA Hubble Space Telescope.